Commercial Preparation of Unnatural Amino Acids by Deracemization

描述(申请人提供)：非天然氨基酸是制药、农化和精细化工行业使用的最大类中间体之一。由于它们在单一对映体药物中的应用，特别是在病毒学和肿瘤学领域，对大规模和高光学纯度的这些化合物的需求现在非常大。然而，没有一种合成或生物合成方法被证明具有足够的通用性来广泛地大规模制备这些化合物。里士满化学公司最近开发了一种高效和通用的化学-酶法工艺，通过外消旋原料的去消旋反应高产率地制备了对映体纯的L和D-氨基酸。该方法涉及对映体选择性氨基酸氧化酶生物催化剂和非选择性化学还原催化剂的协同作用，实现了一个对映体的立体转化，从起始外消旋体中可以得到~gt；99%的对映体过量，产品收率超过90%。这种完全在水中进行的方法(从而最大限度地减少了废气)与最大单程产率为50%的拆分过程相比非常有利。我们已经成功地开发了优化流程效率和建立规模竞争经济的方法。然而，目前该工艺的应用范围受到酶生物催化剂底物范围的限制。我们现在建议应用强大的体外酶进化方法来展示生物催化剂的适应性，从而证明制备药物开发所需的许多非天然氨基酸的一般过程。这些氨基酸因其良好的药代动力学特性而具有很高的相关性，但很难用传统方法制备。因此，我们的方法通过降低成本、工艺要求和废物处理，为精细化工和生命科学行业提供了显著的优势。在第一阶段，我们将通过我们目前的工艺生物催化剂的体外进化来分离对空间大的氨基酸具有高活性和对映体选择性的氨基酸氧化酶。在第二阶段，我们将开发可扩展的化学-酶促去消旋化工艺来制备这些非天然氨基酸，并优化关键反应参数，包括底物负载、生物催化剂生产、配方和重复使用，以及产品分离和回收。实验室进化工作的结果将使我们能够使氧化酶生物催化剂适应许多进一步的目标。在第三阶段，将在非天然氨基酸的商业化生产中大规模实施优化的去消旋工艺。这项工作计划将为精细化学工业带来新的通用生物技术，以生产商业规模的手性合成中间体、农用化学品和药品。该项目旨在开发一种经济的酶法合成光学纯非天然氨基酸。这些氨基酸的需求量很大，可用于合成一系列重要的药物化合物，如HIV蛋白酶抑制剂、抗癌药物和抗糖尿病药物。

DESCRIPTION (provided by applicant): Unnatural amino acids represent one of the largest classes of intermediates used by the pharmaceutical, agrochemical and fine chemical industries. Demand for these compounds at large- scale and high optical purity is now very significant, due to their application in single enantiomer pharmaceuticals, particularly for the areas of virology and oncology. No synthetic or biosynthetic method however, has proven sufficiently versatile to prepare these compounds broadly at scale. Richmond Chemical Corporation has recently developed an efficient and general chemo-enzymatic process to prepare enantiomerically pure L- and D- amino acids in high yield by deracemization of racemic starting materials. This method involves the concerted action of an enantioselective amino acid oxidase biocatalyst and a non-selective chemical reducing catalyst to effect the stereo-inversion of one enantiomer and can result in an enantiomeric excess of > 99 % from the starting racemate, with product yields of over 90 %. This approach, conducted entirely in water, (thereby minimizing waste streams) compares very favorably to resolution processes which have a maximum single pass yield of 50 %. We have successfully developed methods to optimize the efficiency of the process and establish competitive economics at scale. However, the current breadth of application of this process is limited by the substrate range of the oxidase biocatalysts. We now propose to apply powerful methods of in vitro enzyme evolution to demonstrate the adaptability of the biocatalysts, and therefore the general process, to prepare many unnatural amino acids required for pharmaceutical development. These amino acids are of high relevance due to their favorable pharmacokinetic properties but are difficult to prepare by traditional methods. As a result, our approach offers significant advantages to the fine chemical and life sciences industries by reducing costs, processing requirements and waste disposal. In Phase I, amino acid oxidases with high activity and enantioselectivity towards sterically bulky amino acids will be isolated through in vitro evolution of our current process biocatalysts. In Phase II we will develop the scalable chemo-enzymatic deracemization processes to prepare these unnatural amino acids and optimize critical reaction parameters including substrate load, biocatalyst production, formulation and re-use, as well as product isolation and recovery. The results of the laboratory evolution work will enable us to adapt the oxidase biocatalysts to many further targets. In Phase III the optimized deracemization processes will be implemented in the commercial manufacture of unnatural amino acids at large-scale. This work plan will result in new general bioprocess technology for the fine chemical industry, to produce chiral synthetic intermediates, agrochemicals and pharmaceuticals at commercial scale. This project is aimed towards the development of an economical enzymatic process for the synthesis of optically pure unnatural amino acids. These amino acids are in great demand for the synthesis of a wide range of important pharmaceutical compounds such HIV protease inhibitors, anti-cancer agents and anti-diabetic drugs.